Alternative Energy
Lecture 3
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Energetic Biotechnology
Bioenergy
Bioenergy refers to the energy produced from biomass. It’s considered a form of renewable energy since the materials used for bioenergy can be replenished relatively quickly. Through photosynthesis, biomass contains within it stored chemical energy from sunlight, which is why we refer to bioenergy as renewable energy. Unlike fossil fuels, bioenergy be grown.
https://taraenergy.com/blog/a-closer-look-at-bioenergy-biofuels-and-biomass/
Bioenergy is based on plant- and animal-based materials. For example, dung, grasses, and wood products were early biofuels that people used to produce energy. In some societies, they are still widely in use. Nowadays, biomass is a versatile renewable energy source. It can be converted into liquid transportation fuels that are equivalent to fossil-based fuels, such as gasoline, jet, and diesel fuel. Bioenergy technologies enable the reuse of carbon from biomass and waste streams into reduced-emissions fuels for cars, trucks, jets and ships; bioproducts; and renewable power.
https://justenergy.com/blog/bioenergy-biofuels-biomass-what-they-are-how-we-use/
https://learnbioenergy.org/what-is-bioenergy
Main types of bioenergy:
Biofuels
Liquid
Biogas
Solid Biomass
Wood and Agricultural Residues
Pellets and Briquettes
Microbial Fuel Cells
https://green.org/2024/01/30/advantages-and-challenges-of-using-biofuels/
https://frontis-energy.com/2021/01/10/pilot-scale-microbial-fuel-cells-produce-electricity-from-wastewater/
Main types of bioenergy:
1. Biofuels
Bioethanol: Produced by fermenting the sugars in crops like corn, sugarcane, or cellulosic biomass. Bioethanol is primarily used as an additive in gasoline to reduce emissions.
Biodiesel: Made from vegetable oils, animal fats, or recycled greases. It can be used in diesel engines either pure or blended with petroleum diesel.
Video (10 min):
https://www.youtube.com/watch?v=rlVukCEyJ8Y
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Biofuels are categorized as first to fourth generations:
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First-Generation Biofuels
typically sourced from food crops. The three most common types of food crop-based biofuels are sugarcane, soy, and corn.
Also referred to as advanced biofuels, second-generation biofuels are produced from biomass that isn’t sourced from food crops. Use grasses or trees grown on marginal land.
Use algae as energy source.
Second-Generation Biofuels
Third-Generation Biofuels
Fourth-Generation Biofuels
Use of genetic engineering to increase desired traits of organisms used in biofuel production.
https://taraenergy.com/blog/a-closer-look-at-bioenergy-biofuels-and-biomass/
https://justenergy.com/blog/bioenergy-biofuels-biomass-what-they-are-how-we-use/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10063169/
Biomass for First-Generation Biofuels
1. Corn (Maize):
Corn is a versatile biofuel crop used primarily in the production of ethanol. The United States is a prominent producer of corn-based ethanol, using a process that converts corn starch into fermentable sugars and subsequently into ethanol through fermentation. Corn-based ethanol is often blended with gasoline to reduce emissions and dependence on fossil fuels.
2. Sugarcane:
Sugarcane is a biofuel crop widely cultivated in tropical regions, particularly in Brazil. Sugarcane’s high sucrose content makes it an excellent material for bioethanol production. The Brazilian experience demonstrates the viability of using sugarcane to produce ethanol, contributing significantly to the country’s energy independence.
Biomass for First-Generation Biofuels
3. Soybeans:
Soybeans are utilized in the production of biodiesel, an alternative to traditional diesel fuel. Soybean oil, extracted from soybeans, is transformed through a process called transesterification into biodiesel.
The United States is a major producer of soy-based biodiesel, and its usage contributes to reducing greenhouse gas emissions from the transportation sector.
4. Camelina:
Camelina, also known as false flax or gold-of-pleasure, is an oilseed crop with a high oil content. Its seeds can be processed to yield biojet fuel, making it an attractive feedstock for the aviation industry’s efforts to reduce emissions.
Camelina’s ability to grow in dry conditions without requiring significant water resources further contributes to its appeal.
5. Cassava - tuberous edible plant of the spurge family (Euphorbiaceae) from the American tropics. It is cultivated throughout the tropical world for its tuberous roots, from which cassava flour, breads, tapioca, a laundry starch, and an alcoholic beverage are derived. It’s poisonous, and Indigenous peoples developed a complex refining system to remove the poison by grating, pressing, and heating the tubers. The Ethanol production process has 5 main steps: Grinding (prepare cassava to make suitable for downstream processing); Liquefaction; Saccharification; Fermentation and Distillation.
6. Sorghum - approximately one-third of the U.S. grain sorghum crop is used for ethanol production. Naturally drought tolerant, sorghum gives ethanol producers in water-stressed areas a smart choice to help farmers preserve regional resources. A diverse crop, sorghum can be used for many different types of ethanol production. A starch source, sugar source and cellulose source all in a single species, sorghum can be used to produce ethanol using a multitude of platforms.
https://www.britannica.com/plant/cassava
https://www.sorghumcheckoff.com/sustainability/renewable-energy/#:~:text=A%20starch%20source%2C%20sugar%20source,as%20a%20bushel%20of%20corn.
1. Jatropha:
Jatropha is an intriguing biofuel crop due to its ability to thrive in arid and marginal lands, minimizing competition with food crops.
Its seeds yield oil that can be converted into biodiesel. Countries like India, Indonesia, and parts of Africa are exploring the potential of jatropha as a sustainable biofuel feedstock.
2. Switchgrass:
Switchgrass is a native North American grass that has garnered attention for its potential as a biomass feedstock for cellulosic ethanol production.
Its fibrous structure and high cellulose content make it a suitable candidate for converting cellulose into ethanol through advanced biochemical processes. This crop holds promise in reducing land use conflicts as it can grow on marginal lands not suitable for food crops.
Biomass for Second-Generation Biofuels
3. Miscanthus:
Miscanthus is a perennial grass that exhibits rapid growth and high biomass yield. Its potential as a feedstock for both bioethanol and bioenergy production has gained attention.
Miscanthus’ efficient use of water and nutrients, coupled with its potential to sequester carbon, positions it as an environmentally friendly biofuel crop.
And a lot of candidates with good growth – bamboo, willow, paulownia etc.
Biomass for Second-Generation Biofuels
Video (5 min):
https://www.youtube.com/watch?v=d11rdCkUusU
Video (3 min):
https://www.youtube.com/watch?v=Dte9rlwP2po
Biomass for Third-Generation Biofuels
Two primary features that make algae a potential biofuel producer are:
For example, 50% of Botryococcus spp dry mass contains long-chain hydrocarbons.
Microalgae, including diatoms, green algae, eustigmatophytes, golden brown, and prymnesiophytes, are mostly investigated as potential biofuel candidates. The major advantage of using single-celled microalgae is the ease of applying high-throughput technologies to rapidly evolve strains.
Compared to terrestrial crop plants, algae are a better source of biomass for biofuels due to their capacity to remediate wastes from streams or municipal wastewater.
https://www.azocleantech.com/article.aspx?ArticleID=1842
The next species are the most often used for biofuel production:
Chlorella - aquatic unicellular green algae (Chlorophyceae).
This type of algae is a photosynthetic eukaryote characterized by high growth rates and high population densities. Under good conditions, green algae can double its biomass in less than 24 hours. Green algae can also have high lipid contents, usually over 50%. This high yield is ideal for intensive agriculture and can be an excellent source for biodiesel production.
https://microbewiki.kenyon.edu/index.php/Biodiesel_from_Algae_Oil
Algae-filled tubes in a bioreactor
system that produces
biodiesel fuel.
Biomass for Third-Generation Biofuels
The next species are the most often used for biofuel production:
Dunaliella - a unicellular green algae also belonging to the class of Chlorophyceae. It too is a primary algae. The organisms are simple to cultivate and do not clump or form chains. Dunaliella tertiolecta is a marine green flagellate with a size of 10 to 12 μm in diameter. This strain is said to have an oil yield of about 37%. D. tertiolecta is a fast growing strain, therefore allowing it to have a high carbon dioxide rate.
Scenedesmus dimorphus is a unicellular algae in the class Chlorophyceae . Is one of the preferred species for oil yield for biodiesel, but there is a problem: it is heavy, and forms thick sediments if not kept in constant agitation.
https://microbewiki.kenyon.edu/index.php/Biodiesel_from_Algae_Oil
Video (6 min):
https://www.youtube.com/watch?v=yCNkmi7VE0I
Video (10 min):
https://www.youtube.com/watch?v=JvY6ER6HPew
Video (2 min):
https://www.youtube.com/watch?v=JLEWZkKn1GE
Biomass for Third-Generation Biofuels
Video (2 min): https://www.youtube.com/watch?v=GshHN4r7FZI
Video (4 min): https://www.youtube.com/watch?v=CP6uP5Uvih4
G, Baskar & Selvakumari,
I. & Aiswarya, R.
Marine Algae-Future
Source of Biofuels. 72-82.
Producers for Fourth-Generation Biofuels
https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-024-02461-0
Methodology of enhancing lipid accumulation in microalgae cells. Nutrient deficiency, saline stress, light, temperature, CO2, and NaHCO3 can induce lipid accumulation in microalgae
Video (8 min):
https://www.youtube.com/watch?v=5HgMeY4zzDU
Biogas
Biogas is produced through the processing of various types of organic waste. It is a renewable and environmentally friendly fuel made from 100% local feedstocks that is suitable for a diversity of uses including road vehicle fuel and industrial uses.
Materials suitable for biogas production include:
- biodegradable waste from enterprises and industrial facilities, such as surplus lactose from the production of lactose-free dairy products
- spoiled food from shops
- biowaste generated by consumers
- sludge from wastewater treatment plants
- manure and field biomass from agriculture.
https://www.gasum.com/en/gasum/products-and-services/biogas-and-liquefied-biogas/how-is-biogas-produced/
Stages in biogas production:
Biogas is produced using well-established technology in a process involving several stages:
The residual solids and liquids created in biogas production are referred to as digestate. This digestate goes into a post-digester reactor and from there further into storage tanks. Digestates are well suited for uses such as fertilization of fields.
https://www.gasum.com/en/gasum/products-and-services/biogas-and-liquefied-biogas/how-is-biogas-produced/
Video (7 min):
https://www.youtube.com/watch?v=ASoXPy8RWlQ
Video (5 min):
https://www.youtube.com/watch?v=ivWnYxNw1VE
Video (5 min):
https://www.youtube.com/watch?v=Ct3yOcwWShw
Solid Biomass Energy
Solid biomass such as wood, charcoal and agricultural residues has been used since ancient times for cooking and heating purposes – and more recently to generate electricity.
https://energypedia.info/wiki/Portal:Solid_Biomass
Almost all forms of energy or biomass, were or are driven by solar energy. When , fossil fuels, wind managed sustainable, i.e. harvest does not exceed growth, biomass is a renewable energy. Through the mechanism of photosynthesis solar energy is bound into chemical energy in the plants. Thereby it gets usable for humans in form of eating or burning.
Briquetting or pelletizing is the process to improve the characteristics of biomass as a renewable energy resource by densification. Densification means less volume needed for the same amount of energy output.
https://www.briquette-machine.com/global-biomass-briquette-market-outlook-report.html
Solid Biomass Energy
https://energypedia.info/wiki/Biomass_Briquettes_%E2%80%93_Production_and_Marketing
https://www.biopelletmachine.com/biopellet-making-guidance/what-is-biopellets.html
https://www.briquette-machine.com/global-biomass-briquette-market-outlook-report.html
Video (4 min):
https://www.youtube.com/watch?v=6w89dNDpNEA
Video (3 min):
https://www.youtube.com/watch?v=6gaftYQ_56Y
Solid Biomass Energy
Difference between pellets and briquettes:
http://www.pelletequipments.com/blogs/pellets-or-briquettes.html#:~:text=Their%20biggest%20difference%20is%20volume,difference%20is%20%22raw%20material%22.
https://hitechagroenergy.wordpress.com/2017/04/05/difference-between-biomass-pellets-and-biomass-briquettes/
Liquid and gas biofuels are produced by microbiological processes.
Solid biomass energy is produced directly from wood and residues.
You should not mismatch ‘biopellets’ for energy with ‘biopellets’ for cleaning water in aquarium tanks: they are not the energy source, they are used for immobilization wastes and utilizing it by help of anaerobic bacteria within the biopellet.
Such ‘biopellets’ work like filters.
Video (43 min): https://www.youtube.com/watch?v=I9arI2e5bkw
End of Lecture 3